president obama having a slight advantage over mr. romney. >>> wl, with just four days now to go, both candidates are choosing their final campaign stops carefully. in battleground virginia it will play a prominent role again this weekend. northern virginia bureau chief julie carey tells us what both sides are doing now to win the commonwealth. >> reporter: with four days to go campaign offices are gearing up for their most intense weekend of all. the final push to turn out voters. at this fairfax county gop office, volunteers and staffers kept the phone banks going while preparing for the weekend's door-to-door work. at the obama office in manassas a similar picture. supporters also stopped by to get tickets to a rally tomorrow night in prince william county, featuring president obama and former president bill clinton. >> each candidate understands that virginia could be not only a critical swing state in the electoral college but perhaps even the critical state to the outcome. so it's no surprise, therefore, that the candidates are